Solved the LaTeX2exp error. Closes plotly#2027 (plotly#2030)

Co-authored-by: Carson Sievert <[email protected]>

Author: moutikabdessabour

Diff for: R/ggplotly.R

@@ -1303,6 +1303,7 @@ italic <- function(x) paste("<i>", x, "</i>")
 
 # if a vector that has one unique value (ignoring missings), return that value
 uniq <- function(x) {
+  x <- remove_class(x, "TeX")
   u <- unique(x)
   if (identical(u, NA) || length(u) == 0) return(u)
   u <- u[!is.na(u)]
@@ -1433,4 +1434,4 @@ getAesMap <- function(plot, layer) {
   } else {
     layer$mapping
   }
-}
+}

Diff for: tests/testthat/_snaps/latex2exp/latex2exp-rendering.svg

@@ -51,12 +51,12 @@ write_plotly_svg <- function(p, file) {
 
   # strip out non-deterministic fullLayout.uid
   # TODO: if and when plotly provides an API to pre-specify, use it!
-  svg_txt <- readLines(file, warn = FALSE)
+  svg_txt <- readLines(basename(file), warn = FALSE)
   strextract <- function(str, pattern) regmatches(str, regexpr(pattern, str))
   def <- strextract(svg_txt, 'defs id=\\"defs-[[:alnum:]]+\\"')
   uid <- sub("defs-", "", strextract(def, "defs-[[:alnum:]]+"))
   svg_txt <- gsub(uid, "", svg_txt, fixed = TRUE)
-  writeLines(svg_txt, file)
+  writeLines(svg_txt, basename(file))
 }
 
 # copied from vdiffr

Diff for: tests/testthat/helper-vdiffr.R

@@ -0,0 +1,9 @@
+library(latex2exp)
+
+test_that("latex2exp expressions render correctly", {
+  p <- qplot(1, "A")+
+    ylab(TeX("$\\frac{2hc^2}{\\lambda^\\beta}$"))+
+    xlab(TeX("$\\alpha$"))
+
+  expect_doppelganger(config(ggplotly(p), mathjax="cdn"), "latex2exp-rendering")
+})